How did Sai Baba demonstrate his omniscience specifically to his devotee, Cholkar?

Sai Baba demonstrated his omniscience to Cholkar in a deeply personal and striking manner. After Cholkar finally managed to visit Shirdi to fulfill a long-delayed vow, he distributed sugar as promised. He had also been secretly abstaining from sugar as a penance for the delay. The truly miraculous moment, described in Chapter 15, occurred when Baba, who did not drink tea himself, specifically instructed Cholkar's host to 'Give him cups of tea, well-filled with sugar.' This instruction proved to Cholkar that Baba knew the secret details of his vow, the delay, and his personal renunciation of sugar, confirming that Baba was aware of everything in his devotee's mind and life, regardless of physical distance.